usnic: rearrange component struct field order

Just trying to be deliberate about keeping fastpath-accessed fields
grouped together to fit into the same 64-byte cache line.

Reviewed-by: Jeff Squyres <jsquyres@cisco.com>

cmr=v1.7.5:ticket=trac:4253

This commit was SVN r30837.

The following Trac tickets were found above:
  Ticket 4253 --> https://svn.open-mpi.org/trac/ompi/ticket/4253

ompi/mca/btl/usnic/btl_usnic.h

@@ -125,16 +125,14 @@ typedef struct ompi_btl_usnic_component_t {
     /** base BTL component */
     mca_btl_base_component_2_0_0_t super;
 
+    /* in the v1.6 series, sizeof(super) is 256, leading to good alignment for
+     * subsequent fastpath fields */
+
     /** Maximum number of BTL modules */
     uint32_t max_modules;
     /** Number of available/initialized BTL modules */
     uint32_t num_modules;
 
-    char *if_include;
-    char *if_exclude;
-    char *vendor_part_ids_string;
-    uint32_t *vendor_part_ids;
-
     /* Cached hashed version of my RTE proc name (to stuff in
        protocol headers) */
     uint64_t my_hashed_rte_name;
@@ -144,12 +142,22 @@ typedef struct ompi_btl_usnic_component_t {
     /** array of pointers to active BTLs (num_modules elements) */
     struct ompi_btl_usnic_module_t** usnic_active_modules;
 
+    /** convertor packing threshold */
+    int pack_lazy_threshold;
+
+    /* vvvvvvvvvv non-fastpath fields go below vvvvvvvvvv */
+
     /** list of usnic proc structures */
     opal_list_t usnic_procs;
 
     /** name of memory pool */
     char* usnic_mpool_name;
 
+    char *if_include;
+    char *if_exclude;
+    char *vendor_part_ids_string;
+    uint32_t *vendor_part_ids;
+
     /** Want stats? */
     bool stats_enabled;
     bool stats_relative;
@@ -177,9 +185,6 @@ typedef struct ompi_btl_usnic_component_t {
 
     /** retrans characteristics */
     int retrans_timeout;
-
-    /** convertor packing threshold */
-    int pack_lazy_threshold;
 } ompi_btl_usnic_component_t;
 
 OMPI_MODULE_DECLSPEC extern ompi_btl_usnic_component_t mca_btl_usnic_component;